Teens fight aliens but can’t halt story’s destruction

It’s the end of the world as we know it — yet again — in “The 5th Wave,” a largely silly sci-fi action-thriller with a wobbly narrative based on the bestselling young adult novel by Rick Yancey. With two subsequent books in the series, can a movie franchise be far behind? Let’s hope not.

A landlocked Ohio suburb is apparently the Earth’s safest place after an ill-defined alien invasion wreaks havoc on every island and coastal spot on the globe. The mayhem comes in waves: an electromagnetic pulse wipes out the world’s power and water supply, earthquakes beget disastrous tsunamis, avian flu spreads like wildfire and aliens undetectably start occupying human bodies.

But it’s that pesky “5th wave” that surviving Buckeyes must prepare to battle — if they can only figure out what’s coming. To that end, a “Soylent Green is people” type revelation provides fleeting intrigue and a few twists. But it’s insufficiently mined in the clunky script by Susannah Grant (“Erin Brockovich”), Akiva Goldsman (“A Beautiful Mind”) and Jeff Pinkner (“The Amazing Spider-Man 2”).

At the epicenter is Cassie (Chloë Grace Moretz), an average high school student with loving parents (Ron Livingston, Maggie Siff), an adoring kid brother, Sam (Zackary Arthur), and a crush on dreamy classmate, Ben (Nick Robinson).

However, when the aliens strike and tragedy hits home, Cassie remarkably turns all teen-Terminator — one slapdash lesson in guns and she’s good to go. Cassie’s soon tearing through the local rubble in search of little Sam, from whom she’s become separated in a predictable scene involving a forgotten teddy bear.

Meanwhile, the no-nonsense Col. Vosch (Liev Schreiber) and his even tougher second, Col. Reznik (a nearly unrecognizable Maria Bello), draft bands of young folks — including Sam, Ben and the hostile Ringer (Maika Monroe) — to undergo military-style training to combat the aliens or “the others.” It all plays very phony baloney.

Wait, have we lost Cassie? In what seems a separate universe, she’s rescued from injury by a startlingly goodlooking farm boy, Evan (Alex Roe). Can she trust him? Enough, it seems, to propel an unconvincing romance with the well-armed hunk.

These parallel story lines finally intersect but in a way that’s far-fetched, facile and a bit anticlimactic, despite some bone-cracking action. To the movie’s credit, it contains several eye-popping scenes of alien-inspired devastation, and it eschews dystopian tropes for a more intimate, reality-based setting.

But director J Blakeson can’t quite maintain the film’s momentum while squaring its disparate parts, malleable story rules (weren’t all power sources destroyed?), hokey dialogue and a crisscross of often onenote emotions. Still, undemanding teens may buy its message of youthful empowerment.